Actually not always.
in reply to Re: Am I Allowed to Make a New Compiler/Language using Perl?
in thread Am I Allowed to Make a New Compiler/Language using Perl?
You'll often find license agreements which state that the output of the program, your image, is owned by the maker of the software since your image is a derivative of the software and therefore the copyright is owned by the maker. I dont think this has ever been enforced in any court, and the bad PR would ban the maker's software from every corporation in the world, so no maker dares enforce it.